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This report continues the process of documenting the 82 species of mammals and 8 amphibians known to occur, or have recently occurred, In Southeast Alaska. Species accounts are based on a review of the literature, examination of specl mens and associated field notes at natural history museums, and a series of expeditions we conducted through 1999 through the University of Alaska Museum of the North. Our primary conclusion from this survey is that information as basic as distribution and taxonomic status is unavailable for most species of mammals and amphibians. Most species are poorly documented with 53% of mammals represented by fewer than 10 specimens for the entire region. Cetacean material is especially lacking. Minimal documentation also characterizes amphibians. Beyond simply documenting the diStribution of species, serious investigations of these organisms have been hampered by lack of specimens and associated materials. Many investigations aimed at assessing changes in populations over space and time cannot be completed for the majority of species in this region, effectively obviating attempts to monitor health of these wildli fe populations or their response to environmental perturbation. If we examine particular Islands for individual species, a parallel situation arises. Across the archipelago, 111 Islands have at least one specimen that documents the occurrence of any species. Of those "species present" Islands, however, 41% are represented by =<10 specimens of any species. This weak foundation will serve as the basis for future management actions, I ncludlng those aimed at monitoring decl ining native populations or mitigating the Impact of exotics, unless a concerted effort to Inventory this biotic diversity is Initiated. Now Is the time to fill the gaps In our knowledge by building a rigorous, diverse, and well-distributed archive of specimens for the flora and fauna of this coastal region. This preliminary Inventory of the mammals and amphibians reveals serious conservation concerns due to the heavy footprint of humans, particularly on islands with high potential for endemism. In particular, forest fragmentation In the last 50 years has resulted In extensive tracts of closed-canopy forests; these second growth forests support a much less diverse vertebrate fauna. Other human activities may also impact this fauna. Molecular genetic studies of selected species suggest common biogeographic histories for particular elements of the fauna. High levels of genetic differentiation characterize some species and reflect the Influence of a long history of regionai fragmentation due to giaciation. In several cases, multi pie cryptic species have been identified (e.g., two species of marten) and contact or hybrid zones have been documented. At the population level, low levels of variation for some Island populations Is attributable to Isolation and these populations may be especially vulnerable to disturbance. These metrics Indicate the Influence of both historical and contemporary processes on structuring biotic diversity. Such complexity also points to the necessity of prioritizing conservation of endemic forms by buildIng a new "Island-centered" framework for managing wildli fe on the Tongass National Forest and surrounding lands of Southeast Alaska. Such a management paradigm for this complex archipelago should recognize the unique evolutionary and ecological attributes of this Isolated region of North America.



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Special Publication Museum of Southwestern Biology 8